Introduction

ThingsBoard is an open-source server-side platform that allows you to monitor and control IoT devices.
It is free for both personal and commercial usage and you can deploy it anywhere.
If this is your first experience with the platform we recommend to review
what-is-thingsboard page and getting-started guide.

This sample application will allow you to control GPIO of your Raspberry Pi device using ThingsBoard web UI. We will observe GPIO control using Led connected to one of the pins.
The purpose of this application is to demonstrate ThingsBoard RPC capabilities.

Raspberry Pi will use simple application written in Python that will connect to ThingsBoard server via MQTT and listen to RPC commands.
Current GPIO state and GPIO control widget is visualized using built-in customizable dashboard.

Prerequisites

List of hardware and pinouts

Raspberry Pi - we will use Raspberry Pi 3 Model B but you can use any other model.

Led and corresponding resistor

2 female-to-male jumper wires

Wiring schema

Since our application will allow controlling the state of all available GPIO pins, we recommend attaching some LEDs to those pins for visibility.
You can use this basic instruction or another one to wire some LEDs.

Programming the Raspberry Pi

MQTT library installation

The following command will install MQTT Python library:

sudo pip install paho-mqtt

Application source code

Our application consists of a single python script that is well documented.
You will need to modify THINGSBOARD_HOST constant to match your ThingsBoard server installation IP address or hostname.
Use “demo.thingsboard.io” if you are using live demo server.

The value of ACCESS_TOKEN constant corresponds to sample Raspberry Pi device in pre-provisioned demo data.
If you are using live demo server - get the access token for pre-provisioned “Raspberry Pi Demo Device”.

importpaho.mqtt.clientasmqttimportRPi.GPIOasGPIOimportjsonTHINGSBOARD_HOST='YOUR_THINGSBOARD_IP_OR_HOSTNAME'ACCESS_TOKEN='RASPBERRY_PI_DEMO_TOKEN'# We assume that all GPIOs are LOWgpio_state={7:False,11:False,12:False,13:False,15:False,16:False,18:False,22:False,29:False,31:False,32:False,33:False,35:False,36:False,37:False,38:False,40:False}# The callback for when the client receives a CONNACK response from the server.defon_connect(client,userdata,rc,*extra_params):print('Connected with result code '+str(rc))# Subscribing to receive RPC requestsclient.subscribe('v1/devices/me/rpc/request/+')# Sending current GPIO statusclient.publish('v1/devices/me/attributes',get_gpio_status(),1)# The callback for when a PUBLISH message is received from the server.defon_message(client,userdata,msg):print'Topic: '+msg.topic+'\nMessage: '+str(msg.payload)# Decode JSON requestdata=json.loads(msg.payload)# Check request methodifdata['method']=='getGpioStatus':# Reply with GPIO statusclient.publish(msg.topic.replace('request','response'),get_gpio_status(),1)elifdata['method']=='setGpioStatus':# Update GPIO status and replyset_gpio_status(data['params']['pin'],data['params']['enabled'])client.publish(msg.topic.replace('request','response'),get_gpio_status(),1)client.publish('v1/devices/me/attributes',get_gpio_status(),1)defget_gpio_status():# Encode GPIOs state to jsonreturnjson.dumps(gpio_state)defset_gpio_status(pin,status):# Output GPIOs stateGPIO.output(pin,GPIO.HIGHifstatuselseGPIO.LOW)# Update GPIOs stategpio_state[pin]=status# Using board GPIO layoutGPIO.setmode(GPIO.BOARD)forpiningpio_state:# Set output mode for all GPIO pinsGPIO.setup(pin,GPIO.OUT)client=mqtt.Client()# Register connect callbackclient.on_connect=on_connect# Registed publish message callbackclient.on_message=on_message# Set access tokenclient.username_pw_set(ACCESS_TOKEN)# Connect to ThingsBoard using default MQTT port and 60 seconds keepalive intervalclient.connect(THINGSBOARD_HOST,1883,60)try:client.loop_forever()exceptKeyboardInterrupt:GPIO.cleanup()

Running the application

This simple command will launch the application:

python gpio.py

Data visualization

In order to simplify this guide, we have included “Raspberry PI GPIO Demo Dashboard” to the demo data that is available in each Thingboard installation.
You still can modify this dashboard: tune, add, delete widgets, etc.
You can access this dashboard by logging in as a tenant administrator. Use

Once logged in, open Dashboards->Raspberry PI GPIO Demo Dashboard page. You should observe demo dashboard with GPIO control and status panel for your device.
Now you can switch status of GPIOs using control panel. As a result, you will see LEDs status change on the device and on the status panel.

Below is the screenshot of the “Raspberry PI GPIO Demo Dashboard”.

Next steps

Browse other samples or explore guides related to main ThingsBoard features: